Proteomics study of serum exosomes in Kawasaki disease patients with coronary artery aneurysms

BACKGROUND: To study the protein profile of the serum exosomes of patients with coronary artery aneurysms (CAA) caused by Kawasaki disease (KD). METHODS: Two-dimensional electrophoresis (2-DE) was used to identify proteins from the exosomes of serum obtained from children with CAA caused by KD, as well as healthy controls. Differentially expressed proteins were identified using matrix-assisted laser desorption/ionization time-of-flight/time-of-flight mass spectrometry (MALDI-TOF/TOF MS) analysis. RESULTS: Thirty two differentially expressed proteins were identified (18 up-regulated and 14 downregulated) from serum exosomes of children with CAA and were compared to healthy controls. The expression levels of 4 proteins (TN, RBP4, LRG1, and APOA4) were validated using Western blotting. Classification analysis and protein–protein network analysis showed that they are associated with multiple functional groups, including host immune response, inflammation, apoptotic process, developmental process, and biological adhesion process. CONCLUSIONS: These findings establish a comprehensive proteomic profile of serum exosomes from children with CAA caused by KD, and provide additional insights into the mechanisms of CAA caused by KD.